Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS5515359 A
Publication typeGrant
Application numberUS 08/297,270
Publication dateMay 7, 1996
Filing dateAug 26, 1994
Priority dateAug 26, 1994
Fee statusPaid
Publication number08297270, 297270, US 5515359 A, US 5515359A, US-A-5515359, US5515359 A, US5515359A
InventorsOin Zheng
Original AssigneeMitsubishi Electric Research Laboratories, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Credit enhanced proportional rate control system
US 5515359 A
Abstract
A system for controlling traffic in a digital communication network to avoid data loss due to congestion utilizes an integrated credit-based and rate-based traffic control approach, and adjusts the rate at which data is transmitted from a source in accordance with feedback in the form of rate and credit adjustment information from a network reflecting the ability of the network to transmit data and the destination to receive data. In one embodiment, a source end system sends out resource management cells composed of various fields containing rate and credit information. The intermediate systems of the network and the destination end system update the corresponding fields according to their congestion status and send the resource management cells back to the source end system so that the source end system controls the data transmission accordingly. In a preferred embodiment, a source end system calculates an allowed cell rate from each of the fields in a resource management cell, and the minimum one among them is used to control data transmission.
Images(7)
Previous page
Next page
Claims(6)
What is claimed is:
1. A system for controlling traffic in a digital communication network accommodating multiple types of flow control and having a number of nodes and connection paths between nodes established by switches at said nodes, with selected switches of said network having either rate-based or credit-based flow control systems, comprising:
a source end system at an upstream node of said system for controlling the transmission of cells of data along a connection path from said upstream node through an intermediate node of said network to a destination end system at a downstream node by adjusting the cell transmission rate of cells transmitted by said source end system, said source end system including means for transmitting resource management cells with said cells of data, said resource management cells containing at least one field having credit information and one field having rate information to accommodate the multiple types of flow control;
means at said intermediate node for writing information into at least one of said resource management cells for updating the corresponding resource management cell field to reflect the level of congestion at said intermediate node on a credit or rate basis and for transmitting said updated field to said upstream node, and
means at said source end system for adjusting said cell transmission rate based on said updated field from said intermediate node, such that for intermediate nodes having different types of flow control, either credit based or rate based, resource management cells at said nodes are permitted to convey feedback information to said source end system regardless of the type of flow control.
2. The system of claim 1, wherein said credit information includes a credit value.
3. The system of claim 2 wherein said means for adjusting includes means for merging the credit values from all of the nodes associated with said connection path and for adjusting cell transmission rate or limiting cell transmission based on a merged credit value.
4. The System of claim 3 wherein said network includes at least one node downstream of said intermediate node and wherein said updating means includes means for merging the credit values associated with resource management cells received from said downstream node and means for generating resource management cells to be transmitted upstream.
5. The System of claim 3 wherein said source end system includes means for converting a credit value into a rate value and means for coupling said rate value to said adjusting means.
6. The System of claim 3, and further including means for selecting for adjusting said transmission rate to the lesser of the credit values associated with either a rate-based node or a credit-based node.
Description
FIELD OF THE INVENTION

This invention relates to traffic control in a digital communication network and more particularly to a system for controlling data transmission to minimize data loss while accommodating bursty data traffic.

BACKGROUND OF THE INVENTION

In a transmission of data over a digital communication network, such as an asynchronous transfer mode or ATM network, problems arise when multiple sources send data cells or packets at widely varying rates through a switch node or link of the network at an aggregated rate which taxes the ability of that switch node or link to handle the data. Congestion occurs at the node of a network when data arrives at the node at a rate exceeding the rate at which the node can process and forward the data to other nodes. The excess data then accumulates in buffer storage at the node, which fills at a rate which is the difference between the arrival rate and the processing and forwarding rate. If the congestion persists for long periods of time, the buffer storage will be filled to maximum capacity and any additional data must be discarded.

In an effort to minimize such data loss, there are two types of systems which have been used at a source to prevent or inhibit excess data from entering the network. One such system is a rate-based system in which the rate at which the data is permitted to enter the network is adjusted via a feedback signal from a network reflecting the congestion of the network. This congestion of the network is typically denoted by an explicit forward congestion indication bit or an explicit rate in a form of Resource Management cells fedback to the source node. One such rate controlled system is described in an ATM Forum document #94-0735 entitled "Enhanced PRCA (Proportional Rate-Control Algorithm)" authored by Larry Roberts, August 1994.

A competing system for controlling data transmission uses a credit control approach which guarantees lossless transmission of data cells. The credits are generated starting at a destination node to reflect its ability to receive data. This credit is transmitted back to the next upstream node where this credit is interpreted and modified based on this node's ability to receive data. The process continues through each intermediate node back to the source where the credit at the source reflects all intermediate credits as well as the one from the destination. Typically the credits reflect the unused buffer space at each node. The source then interprets the credit as an indication of the amount of data that it can transmit into the network without any data loss due to congestion or buffer overflow. Note that data rate is not controlled, but the number of cells transmitted is controlled. One such credit controlled system is described in an ATM Forum document #94-0632 entitled "Credit-Based FCVC Proposal for ATM Traffic Management, Revision R2" authored by Doug Hunt, Warner Andrews, Jim Scott, Bob Simcoe, Jon Bennett, H. T. Kung, John Howard, Alan Chapman, and Ken Brinkerhoff, July, 1994.

Each scheme has its advantages and disadvantages. The rate-based scheme relies on end systems to do traffic control. Thus very little intelligence and participation are required on the part of switch nodes of ATM networks. Also, the rate-based paradigm is in accordance with the current standards for ATM traffic management to be implemented on network interface hardware. However, the issues of performance and its ability to react to congestion have been raised about the rate-based scheme. There is no analytical proof or real world experience showing that the rate-based scheme will be able to provide satisfactory performance and minimize cell losses of bursty traffic.

The credit-based scheme, on the other hand, has a solid proof that lossless transmission can be achieved. With its static buffer allocation algorithm, it can also achieve the maximum link bandwidth utilization. However, since the credit-based scheme requires coordination and active participation of all switches in a path, significant changes to the architecture of the existing ATM switches are needed. The switch implementation cost, in terms of processing power and buffer requirement, is also of concern. Thus a main concern about the credit-based scheme is whether or not the scheme is mature enough for wide spread implementation.

Since no single mechanism is believed by all to be shown by simulation and analysis to work well over the wide dynamic range of link speeds and distances and to meet the application requirements, performance, and cost of equipment goals, there is a need to allow both mechanisms be used in a network.

SUMMARY OF INVENTION

In order to accommodate both rate-based and credit-based traffic control mechanisms, an integrated system is provided for controlling traffic in a digital communication network to avoid data loss due to congestion utilizing a single mechanism incorporating features of both the rate-based systems and credit-based systems to feed back information from the destination to the source and control data transmission responsive to this feedback information.

Specifically, a system for controlling traffic in a digital communication network to avoid data loss due to congestion utilizes an integrated credit-based and rate-based traffic control approach, and adjusts the rate at which data is transmitted from a source in accordance with feedback in the form of rate and credit adjustment information from a network, in which the feedback information reflects the ability of the network to transmit data and the destination to receive data. In one embodiment, a source end system sends out resource management cells or RM cells composed of various fields containing rate and credit information. The intermediate systems of the network and the destination end system update the corresponding fields according to their congestion status and send the RM cells back to the source end system so that the source end system controls the data transmission accordingly. In a preferred embodiment, a source end system calculates an allowed cell rate from each of the fields in a RM cell, and uses the minimum one among them to control data transmission.

A main feature of the subject system is that different types of switch nodes in a network set different fields of RM cells to convey congestion information back to a source end system. Thus a source end system can make the maximum use of this rich feedback information and control cell transmission effectively. Also, traffic control scheme is automatically determined by switch nodes on the route instead of being negotiated at the time the connection is set up. For example, if a connection goes through rate-based switches only, then only rate related fields of RM cells are set. Consequently, cell transmission is controlled by a rate based scheme only. If a connection goes through credit based switches only, then only credit related fields are set and cell transmission is controlled by a credit based scheme only. Finally, if a connection goes through both rate based and credit based switches, both rate related and credit related fields are set, and cell transmission is controlled by an integrated rate based and credit based scheme.

In this way, the Subject System achieves a seamless integration of rate-based and credit-based traffic control mechanisms since no internetworking devices are required. The integration is also transparent to end users since end users are not bothered with the responsibility of negotiating a traffic control mechanism.

The subject system permits the gradual introduction of more sophisticated systems like credit based switch nodes on a node-by-node basis into existing networks without having to replace every switch node in the network. Additionally, the Subject System provides more information oil which to set transmission rate in existing rate-based networks. Most importantly, the Subject System does not add significant implementation complexity at a rate-based source end system.

BRIEF DESCRIPTION OF DRAWINGS

These and other features of the Subject Invention will be better understood in conjunction with the Detailed Description taken in accordance with the Drawings of which:

FIG. 1 is schematic diagram illustrating a network having a source end system from which data cells and RM cells are transmitted through an intermediate system in the network to a destination end system through user network interfaces, in which RM cells are modified and retransmitted back from a destination end system, forwarded and/or modified by an intermediate system, and received at the source end system and used to control the rate at which data cells are transmitted;

FIG. 2 is a drawing showing the fields in a RM cell used for conveying congestion information in which, explicit forward congestion indication, EFCI, is an explicit forward congestion indication bit that a switch can use to indicate a congestion status, Explicit Rate, ER, is a multi-bit field that a switch may use to set the transmission rate for the source end system, Credit Update, CU, is a multi-bit field that a switch may use to update the credit count at the source end system, and allowed cell rate, ACR, is a multi-bit field that a source end system may use to convey its allowed cell rate information to intermediate systems and destination end system;

FIG. 3 is a schematic diagram illustrating one possible way that an intermediate system in FIG. 1 may use the CU field of RM cells to convey credit update information;

FIG. 4 is a block diagram illustrating a more general structure of an intermediate system in FIG. 1 which is capable of forwarding, generating, updating, and merging RM cells;

FIG. 5 is a block diagram of the source end system of FIG. 1 in which RM cells reflecting the state of the the network are applied to a RM cell processor which generates signals of credit count C, explicit rate ER, and explicit forward congestion indication EFCI applied to an allowed cell rate generator which in turn provides a signal corresponding to the allowed cell rate to a rate controller which governs the rate of transmission of data cells;

FIG. 6 is a block diagram illustrating the internal operation of an ACR generator in FIG. 3 in which incoming signals ER, EFCI, cell-- empty, cell-- out are converted to a cell rate ACR0 using a rate control algorithm such as the proportional rate control algorithm or PRCA, the credit signal C is converted to a cell rate ACR1 using a function f(), and the minimum of ACR0 and ACR1 is outputted as an allowed cell rate; and,

FIG. 7 is a block diagram illustrating the destination end system of FIG. 1 in which incoming data cells are forwarded to a host system, not shown, and RM cells are transmitted back to the source end system via a RM cell retransmitter.

DETAILED DESCRIPTION

Referring now to FIG. 1, a network 10 is utilized to connect a source end system 12 at a source node to a destination end system 14 at a destination node via an intermediate system 16 at an intermediate node by providing a user network interface 18. The source end system transmits data cells along with RM cells for each virtual channel as indicated by dotted line 20 to the destination end system. A virtual channel or VC is a logical stream of data from one application in the source to one application in the destination with a virtual channel established by a connection path from a source node, through one or more intermediate nodes, to a destination node of the network. The RM cells contain the current states of the source end system, traverse through each intermediate system, which may record the state information and update some fields according to its congestion status, on its route to the destination end system. The destination end system 14 may update some fields in a received RM cell and send it back to the source end system 12 along the same route as indicated by the dotted line 22. Each intermediate system on the route may update stone fields in the RM cell according to its congestion status. When a RM cell traverses back to the source end system 12, the information contained in its fields is used by the source end system to adjust the cell transmission rate or limit cell transmission.

Referring now to FIG. 2. In preferred embodiment, for each virtual channel, a source end system transmits one RM cell for every Nrm-1 of data cells sent, where Nrm is a parameter of the virtual channel. Among other things, a RM cell 24 contains an explicit forward congestion notification bit or EFCI bit 26, an explicit rate field or ER field 28, a credit update or CU field 30, and an allowed cell rate or ACR field 32. When sending a resource management cell, the source end system puts the current allowed cell rate of the virtual channel in the ACR field, the current sequence number of cells transmitted of the virtual channel in the CU field. It also sets the ER field to a peak cell rate PCR and EFCI to zero. As described in the proportional rate control algorithm, PRCA, an intermediate system or destination end system may update the EFCI bit from zero to one if it is in a congested state. It may also reduce the value of ER to explicitly reduce the transmission rate at the source.

Referring now to FIG. 3, in one preferred embodiment, a credit enhanced intermediate system 40 maintains a cell count 42 for each virtual channel which records the total number of cells it has forwarded to the destination end system for the virtual channel. Each RM cell 44 received from the source end system is forwarded to the destination end system. For each RM cell 46 received from the destination end system, its CU field is retrieved which may be used to update the credit count for the virtual channel and control the transmission of cells to the destination end system, and the current count value is written into the CU field before the RM cell is sent back to the source end system. Referring now to FIG. 4, besides a forward RM cell processor 52 and a backward RM cell processor 56 which forward and update RM cells, an intermediate system 50 may also have an RM cell generator 54 to generate RM cells itself and send it back to the source end system to speed up the information feedback. To reduce the number of RM cells and save link transmission bandwidth, an RM cell merger 58 may be used which delays and merges RM cells.

Referring now to FIG. 5, RM cells received from the network at a source end system are applied to RM cell processor 60 which extracts information from RM cells and generates signals C, ER, and EFCI which are in turn applied to ACR generator 62, with generator 62 providing an allowed cell rate value, ACR, to be applied to a rate controller 64 which controls the rate at which data cells 66 at the input link 70 to rate controller 64 are permitted to be transmitted over the output link 72. Each time a cell is transmitted, the fact of this transmission is indicated to both generator 62 and RM cell processor 60 via a "cell out" signal applied to line 74. If at the time a cell is to be transmitted, there is no cell waiting, a signal representing "empty cell" is coupled to generator 62 over line 76. In operation, RM cell processor 60 maintains a credit count C based on the RM cells received, diminished by the number of cells transmitted.

Referring now to FIG. 6, ACR generator 62 in FIG. 5 includes a module 80 executing a Proportional Rate Control Algorithm or some other rate control algorithms which converts signals ER, EFCI, cell-- empty, and cell-- out into a rate signal ACR0. A module 82 is also used which converts signal C into a rate signal ACR1 using a function f(). One possible selection of f() is a step function: f(C)=PCR if C is larger than 0, and f(0)=MCR or 0, where PCR is the peak cell rate and MCR. is the minimum cell rate. Another selection is a linear function: f(C)=MCR+(PCR-MCR)C/Cmax, where Cmax is the maximum credit value. Module 84 then selects the minimum of ACR0 and ACR1 as ACR. The ACR generator described here is a key component that realizes the integration of rate control and credit control mechanisms.

Referring now to FIG. 7, destination end system 90 includes a RM cell processor which identifies and updates incoming RM cells which are in turn forwarded to a RM cell retransmitter 94 sending RM cells back to the source end system. Similar to an intermediate system, a RM cell processor 92 at a destination end system 90 call simply forward each arriving RM cell to RM cell retransmitter thus acting as a simple destination end system, or modify various fields in all RM cell before forwarding it to the RM cell retransmitter, thus acting as a rate controlled, credit controlled, or integrated destination end system.

To illustrate the usage of the subject system, Pseudo code describing one possible implementation of a source end system using a credit enhanced PRCA with a step credit control function, a destination end system which sets EFCI bits and sends RM cells back to the source end system, and an credit enhanced intermediate systems as illustrated in FIG. 3 is given below.

______________________________________Source End SystemParameters (per VC):PCR   Peak Cell RateICR   Initial Cell RateMCR   Minimum Cell Rate, the minimum for ACRAIR   Additive Increase Rate (cells/unit-- time)MDF)  Multiplicative Decrease Factor (used as 2Nrm   One RM cell sent for every Nrm cells.Cmax  Maximum credit valueVariables (per VC):ACR       Allowed Cell RateADR       Additive Decrease Ratecount     Number of cells sent.next-- cell-- time     The next opportunity for the VC to send a cell.cell-- sent (flag)     If set, at least one cell was sentC         Credit valueInput events (asynchronous):∘ next-- cell-- time∘ receive RM cellRM cell fields:ACR:  Available Cell Rate in effect when forward RM cell is sentDIR:  Direction of the RM cell (forward or backward)ER:   Explicit rate, initially set to PCR, and possibly modified downward by switches along the pathEFCI: Congestion Indicator (0 = no congestion, 1 = congestion)CU:   Number of cells forwardedPseudoCode:InitializationNetwork assigns values to PCR, ICR, MCR, AIR,MDF, and Cmax.ACR = ICRcount = 0cell-- sent = 0ADR = ShiftR(ACR, MDF)C = CmaxWhile VC-- on-- line doif (now >= next-- cell-- time)if (ACR>ICR or cell-- sent)ACR = max( ACR - ADR, MCR)if cell-- to-- send            Queue not emptysend data cell with EFCI=0if (count mod Nrm = 0)send RM(ACR, DIR=forward, ER=PCR,EFCI=0, CU=count+Cmax)ADR = ShiftR(ACR, MDF)cell-- sent = 1count = count + 1else cell-- sent = 0next-- cell-- time = next-- cell-- time + 1/ACRif receive RM(ACR, DIR=backward, ER, EFCI, CU)C = max (0, Cmax + CF - count)C = min (C, Cmax)if (C = 0)ACR = MCR (or 0)else if (EFCI = 0)ACR = ACR + Nrm*AIR + Nrm*ADRACR = min(ACR, ER)ACR = min(ACR, PCR)ACR = max(ACR, MCR)next-- cell-- time = now + 1/ACRelse if (ACR > ER)ACR = max(ER, MCR)next-- cell-- time = now + 1/ACRDestination End SystemPseudoCode:if(receive data cell)VC-- EFCI = EFCI state of cellif(receive RM(ACR, DIR=forward, ER, EFCI, CU)if(VC-- EFCI=1)EFCI = 1send RM(ACR, DIR = backward, ER, EFCI, CU)Intermediate SystemParameters (per VC):Cmax  Maximum credit value at this intermediate systemVariables (per VC):count Number of cells sentC     Credit valuePseudoCode:InitializationC = Cmaxcount = 0For each cell sent in the forward directioncount = count + 1For each RM cell receivedif (DIR = forward)forward the cellif (DIR=backward)C = max (0, Cmax+CF-count)CF = countif (C = 0)disable the transmission of VCif (C > 0)enable the transmission of VC______________________________________

Having above indicated a preferred embodiment of the present invention, it will occur to those skilled in the art that modifications and alternatives can be practiced within the spirit of the invention. It is accordingly intended to define the scope of the invention only as indicated in the following claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4984264 *Feb 20, 1990Jan 8, 1991Kabushiki Kaisha ToshibaCall admission control method and cell flow monitoring method in the same method
US5115429 *Aug 2, 1990May 19, 1992Codex CorporationDynamic encoding rate control minimizes traffic congestion in a packet network
US5119367 *Oct 25, 1989Jun 2, 1992Oki Electric Industry Co., Ltd.Method and a node circuit for routing bursty data
US5119372 *May 4, 1990Jun 2, 1992At&T Bell LaboratoriesMulti-access ATD multiplexer with congestion detection circuitry
US5199027 *Mar 14, 1989Mar 30, 1993Alcatel N.V.Communication switching system
US5265091 *Feb 13, 1992Nov 23, 1993Alcatel N.V.Adaptation of reserved estimated bandwidth for permanent virtual connection
US5280470 *Feb 3, 1993Jan 18, 1994At&T Bell LaboratoriesBandwidth and congestion management in accessing broadband ISDN networks
US5309431 *Mar 19, 1991May 3, 1994Fujitsu LimitedRoute regulating apparatus
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5680596 *Aug 29, 1995Oct 21, 1997International Business Machines CorporationData transfer apparatus with automatic transmission rate adjustment
US5745477 *Jan 25, 1996Apr 28, 1998Mitsubishi Electric Information Technology Center America, Inc.Traffic shaping and ABR flow control
US5748613 *Mar 29, 1996May 5, 1998Hewlett-Packard CompanyCommunication pacing method
US5748901 *May 21, 1996May 5, 1998Ramot University Authority Ltd.Flow control algorithm for high speed networks
US5751697 *Dec 6, 1995May 12, 1998Pmc-Sierra, Inc.Allowed cell rate reciprocal approximation in rate-based available bit rate schedulers
US5774455 *Jun 20, 1996Jun 30, 1998Fuji Xerox Co., Ltd.Data transmission apparatus and method and data communication system conducting variable bit-rate data transmission
US5787073 *May 29, 1996Jul 28, 1998Nec CorporationATM cell rate control with transmission priority given to control cells for quick response to network congestion
US5805577 *Jul 19, 1996Sep 8, 1998Jain; RajErica: explicit rate indication for congestion avoidance in ATM networks
US5818845 *Jan 18, 1996Oct 6, 1998Hybrid Networks, Inc.Hybrid access system having channel allocation and prioritized polling schemes
US5825748 *Apr 8, 1997Oct 20, 1998International Business Machines CorporationCredit-based flow control checking and correction system
US5831973 *Oct 11, 1996Nov 3, 1998Mitsubishi Denki Kabushiki KaishaMulticast connection control method and apparatus
US5831985 *Aug 5, 1997Nov 3, 1998Emc CorporationMethod and apparatus for controlling concurrent data transmission from multiple sources in a channel communication system
US5838662 *May 30, 1995Nov 17, 1998Fujitsu LimitedSystem and method for transferring data
US5848056 *Mar 20, 1997Dec 8, 1998Alcatel Alsthom, Compagnie Generale D'electriciteMethod to estimate the current datapacket rate of a virtual connection, a feedback mechanism using said method and device, switching node and destination node realizing said method
US5875173 *Jun 5, 1996Feb 23, 1999Nec CorporationCommunication control device and method for use in an ATM system operable in an ABR mode
US5878029 *Feb 12, 1997Mar 2, 1999Nippon Telegraph And Telephone CorporationVariable-bandwidth network
US5898669 *Mar 22, 1996Apr 27, 1999Shimony; IlanATM traffic management device
US5910952 *Aug 22, 1996Jun 8, 1999Fujitsu LimitedCall restriction system for an ATM exchange
US5913074 *Nov 18, 1996Jun 15, 1999Nec CorporationBuffer flow control unit for dynamically counting a number of virtual channels per service class in asynchronous transfer network
US5922046 *Sep 12, 1996Jul 13, 1999Cabletron Systems, Inc.Method and apparatus for avoiding control reads in a network node
US5941952 *Sep 12, 1996Aug 24, 1999Cabletron Systems, Inc.Apparatus and method for transferring data from a transmit buffer memory at a particular rate
US5943316 *May 1, 1996Aug 24, 1999Roke Manor Research LimitedCredit bandwidth allocator for a radio system
US5946322 *Aug 27, 1996Aug 31, 1999Hybrid Networks, Inc.Hybrid access system utilizing credit/done polling protocols
US5963553 *Jul 11, 1997Oct 5, 1999Telefonaktiebolaget Lm EricssonHandling ATM multicast cells
US5970229 *Sep 12, 1996Oct 19, 1999Cabletron Systems, Inc.Apparatus and method for performing look-ahead scheduling of DMA transfers of data from a host memory to a transmit buffer memory
US5987007 *Feb 14, 1997Nov 16, 1999Nokia Telecommunications OyManipulation of header field in ATM cell
US5995995 *Sep 12, 1996Nov 30, 1999Cabletron Systems, Inc.Apparatus and method for scheduling virtual circuit data for DMA from a host memory to a transmit buffer memory
US5999980 *Sep 12, 1996Dec 7, 1999Cabletron Systems, Inc.Apparatus and method for setting a congestion indicate bit in an backwards RM cell on an ATM network
US6018518 *Jan 10, 1997Jan 25, 2000Madge Networks LimitedFlow control in a cell switched communication system
US6044406 *Apr 8, 1997Mar 28, 2000International Business Machines CorporationCredit-based flow control checking and correction method
US6046983 *Apr 1, 1997Apr 4, 2000Nippon Telegraph And Telephone CorporationDynamic rate control system
US6067563 *May 6, 1999May 23, 2000Cabletron Systems, Inc.Method and apparatus for avoiding control reads in a network node
US6084934 *Mar 6, 1997Jul 4, 2000International Business Machines CorporationNatural throttling of data transfer across asynchronous boundaries
US6088359 *Jul 11, 1997Jul 11, 2000Telefonaktiebolaget Lm EricssonABR server
US6091708 *Jun 12, 1997Jul 18, 2000Oki Electric Industry Co., Ltd.Traffic shaper with multiply queued virtual paths
US6091726 *Feb 18, 1997Jul 18, 2000AlcatelDevice and method for handling, assembling and transmission of data packets
US6115358 *Jun 5, 1996Sep 5, 2000General Data Comm, Inc.Controlling the flow of ATM cells in an ATM network
US6141321 *Jul 8, 1997Oct 31, 2000Alcatel Networks CorporationMethod and apparatus for the efficient processing of ABR cells in an ATM switch
US6151300 *May 9, 1997Nov 21, 2000Fujitsu Network Communications, Inc.Method and apparatus for enabling flow control over multiple networks having disparate flow control capability
US6151303 *Jun 5, 1997Nov 21, 2000Nec CorporationMethod of asynchronous transfer mode (ATM) switching and an ATM switching equipment
US6154459 *Jul 11, 1997Nov 28, 2000Telefonaktiebolaget Lm EricssonData shaper for ATM traffic
US6167030 *Mar 20, 1997Dec 26, 2000Nokia Telecommunications, OyBuffer-based traffic measurement system and method for nominal bit rate (NBR) service
US6169748 *Oct 26, 1999Jan 2, 2001Fujitsu Network Communications, Inc.Frame based quality of service
US6178448 *Jun 18, 1997Jan 23, 2001International Business Machines CorporationOptimal link scheduling for multiple links by obtaining and utilizing link quality information
US6185209Jul 11, 1997Feb 6, 2001Telefonaktiebolaget Lm EricssonVC merging for ATM switch
US6192406 *Jun 13, 1997Feb 20, 2001At&T Corp.Startup management system and method for networks
US6215772 *Nov 26, 1997Apr 10, 2001International Business Machines CorporationDynamic parameter estimation for efficient transport of HPR data on IP
US6226265 *Jul 8, 1996May 1, 2001Fujitsu LimitedPacket flow monitor and control system
US6233222 *Mar 6, 1998May 15, 2001Telefonaktiebolaget Lm EricssonTelecommunications inter-exchange congestion control
US6243358 *Feb 4, 1998Jun 5, 2001France TelecomProcess and device for allocating resources in a packet transmission digital network
US6249819Dec 4, 1997Jun 19, 2001Fujitsu Network Communications, Inc.Method for flow controlling ATM traffic
US6256315 *Oct 26, 1999Jul 3, 2001Fujitsu Network Communications, Inc.Network to network priority frame dequeuing
US6349088 *Nov 8, 1996Feb 19, 2002Nokia Telecommunications OyTraffic control in a communication system
US6396807 *Nov 18, 1998May 28, 2002Thomson-CsfMethod for the control of flows of digital information
US6446125 *Mar 28, 1997Sep 3, 2002Honeywell International Inc.Ripple scheduling for end-to-end global resource management
US6452903 *May 31, 2000Sep 17, 2002Fujitsu Network Communications, Inc.Network switch supporting rate-based and credit-based flow control mechanisms on a link-by-link basis
US6463036 *Jan 2, 1997Oct 8, 2002Hitachi, Ltd.ATM communication apparatus and method of controlling congestion in a communication network using the ATM communication apparatus
US6466541May 31, 2000Oct 15, 2002Fujitsu Network Communications, Inc.Cell pacing on a network link employing a rate-based flow control protocol with underlying credit-based flow control mechanisms
US6466997Jun 14, 1999Oct 15, 2002Enterasys Networks, Inc.Method and apparatus for performing TX raw cell status report frequency and interrupt frequency mitigation in a network node
US6493335Sep 24, 1996Dec 10, 2002At&T Corp.Method and system for providing low-cost high-speed data services
US6504821 *Jun 4, 1997Jan 7, 2003At&T Corp.Flexible bandwidth negotiation for the block transfer of data
US6556542 *Aug 14, 1998Apr 29, 2003Fujitsu LimitedTransfer rate controlling device and method thereof
US6590866 *May 22, 1998Jul 8, 2003Fujitsu LimitedCell flowing ratio controlling method and cell switching system using the same
US6657954 *Mar 31, 1999Dec 2, 2003International Business Machines CorporationAdapting receiver thresholds to improve rate-based flow control
US6747949 *Dec 16, 1999Jun 8, 2004Intel CorporationRegister based remote data flow control
US6822939May 20, 2002Nov 23, 2004Transwitch CorporationMethod and apparatus for guaranteeing a minimum cell rate (MCR) for asynchronous transfer mode (ATM) traffic queues
US6862618May 4, 2000Mar 1, 2005International Business Machines CorporationOptimal link scheduling for multiple links
US6876663 *Jun 5, 2001Apr 5, 2005Xyratex Technology LimitedSwitching system
US6944173 *Mar 27, 2000Sep 13, 2005Hewlett-Packard Development Company, L.P.Method and system for transmitting data between a receiver and a transmitter
US6980513Sep 24, 2001Dec 27, 2005Transwitch CorporationMethods and apparatus for the fair allocation of bandwidth among MCR and best effort service connections in an ATM switch
US7072299Aug 20, 2001Jul 4, 2006International Business Machines CorporationCredit-based receiver using selected transmit rates and storage thresholds for preventing under flow and over flow-methods, apparatus and program products
US7136954 *Jan 31, 2005Nov 14, 2006International Business Machines CorporationData communication method and apparatus utilizing credit-based data transfer protocol and credit loss detection mechanism
US7190699May 31, 2002Mar 13, 2007International Business Machines CorporationMethod and apparatus for implementing multiple credit levels over multiple queues
US7277974Oct 27, 2006Oct 2, 2007International Business Machines CorporationData communication method and apparatus utilizing credit-based data transfer protocol and credit loss detection mechanism
US7552077 *Jun 26, 2002Jun 23, 2009Trading Technologies International, Inc.System and method for coalescing market data at a network device
US7567930 *May 2, 2006Jul 28, 2009Trading Technologies International, Inc.System and method for coalescing market data at a network device
US7647435Jun 11, 2007Jan 12, 2010International Business Machines CorporationData communication method and apparatus utilizing credit-based data transfer protocol and credit loss detection mechanism
US7882278Jan 30, 2009Feb 1, 2011International Business Machines CorporationUtilizing programmable channels for allocation of buffer space and transaction control in data communications
US8090637Jun 2, 2009Jan 3, 2012Trading Technologies International Inc.System and method for coalescing market data at a network device
US8229823Nov 29, 2011Jul 24, 2012Trading Technologies International, Inc.System and method for coalescing market data at a network device
US8284671 *Dec 9, 2008Oct 9, 2012Panasonic CorporationData transmitting and receiving system, terminal, relay device, and data transmitting method
US8301546May 17, 2011Oct 30, 2012Trading Technologies International, Inc.System and method for providing market updates in an electronic trading environment
US8352344Jun 19, 2012Jan 8, 2013Trading Technologies International, Inc.System and method for coalescing market data at a network device
US8571959Nov 29, 2012Oct 29, 2013Trading Technologies International, Inc.System and method for coalescing market data at a network device
US8583541Apr 19, 2012Nov 12, 2013Trading Technologies International, Inc.System and method for providing market updates in an electronic trading environment
US8717874Aug 27, 2012May 6, 2014International Business Machines CorporationUpdating a switch software image in a distributed fabric protocol (DFP) switching network
US8750129Oct 6, 2011Jun 10, 2014International Business Machines CorporationCredit-based network congestion management
US8767529Sep 12, 2011Jul 1, 2014International Business Machines CorporationHigh availability distributed fabric protocol (DFP) switching network architecture
US8767722Aug 27, 2012Jul 1, 2014International Business Machines CorporationData traffic handling in a distributed fabric protocol (DFP) switching network architecture
US8797843Aug 27, 2012Aug 5, 2014International Business Machines CorporationHigh availability distributed fabric protocol (DFP) switching network architecture
US8798080Aug 27, 2012Aug 5, 2014International Business Machines CorporationDistributed fabric protocol (DFP) switching network architecture
US20100097924 *Dec 9, 2008Apr 22, 2010Takao YamaguchiData transmitting and receiving system, terminal, relay device, and data transmitting method
US20110276490 *May 7, 2010Nov 10, 2011Microsoft CorporationSecurity service level agreements with publicly verifiable proofs of compliance
WO1996039759A1 *Jun 5, 1996Dec 12, 1996Gen Datacomm Ind IncControlling the flow of atm cells in an atm network
WO1997003549A2 *Jul 18, 1996Feb 6, 1997Ascom Nexion IncPrioritized access to shared buffers
WO1997035407A1 *Mar 20, 1997Sep 25, 19973Com CorpAtm traffic management device
WO1997044724A2 *May 7, 1997Nov 27, 1997Yehuda AfekFlow control algorithm for high speed networks
WO1998025378A1 *Dec 4, 1997Jun 11, 1998Fujitsu LtdMethod for flow controlling atm traffic
Classifications
U.S. Classification370/231, 370/236, 370/232
International ClassificationH04Q3/00, H04L12/56
Cooperative ClassificationH04L2012/5652, H04L12/5602, H04L2012/5635, H04L2012/5632, H04L2012/563
European ClassificationH04L12/56A1
Legal Events
DateCodeEventDescription
Mar 12, 2008ASAssignment
Owner name: BINARY SERVICES LIMITED LIABILITY COMPANY, DELAWAR
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MITSUBISHI ELECTRIC RESEARCH LABORATORIES, INC.;REEL/FRAME:020638/0402
Effective date: 20071207
Nov 5, 2007FPAYFee payment
Year of fee payment: 12
Mar 19, 2004FPAYFee payment
Year of fee payment: 8
Mar 19, 2004SULPSurcharge for late payment
Year of fee payment: 7
Nov 26, 2003REMIMaintenance fee reminder mailed
Jan 23, 2001ASAssignment
Owner name: MITSUBISHI ELECTRIC RESEARCH LABORATORIES, INC., M
Free format text: CHANGE OF NAME;ASSIGNOR:MITSUBISHI ELECTRIC INFORMATION TECHNOLOGY CENTER AMERICA, INC.;REEL/FRAME:011564/0329
Effective date: 20000828
Owner name: MITSUBISHI ELECTRIC RESEARCH LABORATORIES, INC. 20
Free format text: CHANGE OF NAME;ASSIGNOR:MITSUBISHI ELECTRIC INFORMATION TECHNOLOGY CENTER AMERICA, INC. /AR;REEL/FRAME:011564/0329
Oct 27, 1999FPAYFee payment
Year of fee payment: 4
Sep 23, 1996ASAssignment
Owner name: MITSUBISHI ELECTRIC INFORMATION TECHNOLOGY CENTER
Free format text: CHANGE OF NAME;ASSIGNOR:MITSUBISHI ELECTRIC RESEARCH LABORATORIES, INC.;REEL/FRAME:008186/0570
Effective date: 19960424
Aug 26, 1994ASAssignment
Owner name: MITSUBISHI ELECTRIC RESEARCH LABORATORIES, INC., M
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ZHENG, QIN;REEL/FRAME:007126/0750
Effective date: 19940825